Gonadotrophins are hormones that include LH and FSH, which are produced by the pituitary gland. LH and FSH levels are controlled by GnRH from the hypothalamus. FSH stimulates growth of ovarian follicles and testosterone production, while LH stimulates estrogen and progesterone production. Abnormalities in FSH and LH secretion can indicate hypothalamic, pituitary, or gonadal issues and impact fertility.